Ephesians 5:31 in the King James Version
For this cause shall a man leave his father and mother, and shall be joined unto his wife, and they two shall be one flesh.
Context
30 because we are members of his body, of his flesh and bones.
31 “For this cause a man will leave his father and mother and will be joined to his wife. Then the two will become one flesh.”
32 This mystery is great, but I speak concerning Christ and the assembly.